#!/bin/zsh

## inspired by 'https://starship.rs/install.sh' as of 2021-03-07

ZSHU[starship_baseurl]='https://github.com/starship/starship/releases'
## ZSHU[starship_target] is auto-detected
## ZSHU[starship_path] defaults to ZSHU[d_bin] which is in PATH already

# export STARSHIP_CONFIG="$HOME/.config/starship.toml"
# export STARSHIP_CACHE="$HOME/.cache/starship"

__z_starship_auto_path() {
    echo "${ZSHU[starship_path]:-${ZSHU[d_bin]}}"
}

__z_starship() {
    local x=$(__z_starship_auto_path)
    x="$x/starship"
    [ -x "$x" ] || x=starship
    [ -x "$x" ] || return 127
    "$x" "$@"
}

__z_starship_test() { __z_starship -V &>/dev/null ; }

## NB: supply TARGET environment variable to call
__z_starship_url_latest() {
    printf '%s/latest/download/starship-%s.tar.gz' \
           "${ZSHU[starship_baseurl]}" "${TARGET}"
}

## NB: supply TARGET environment variable to call
## $1 - version (semver like '0.50.0')
__z_starship_url_versioned() {
    printf '%s/download/v%s/starship-%s.tar.gz' \
           "${ZSHU[starship_baseurl]}" "$1" "${TARGET}"
}

## NB: install starship somewhere in PATH ;)
__z_starship_ver_installed() {
    __z_starship -V 2>/dev/null \
    | sed -En '/^starship v?(\S.+)$/{s//\1/;p;}'
}

## NB: supply TARGET environment variable to call
__z_starship_ver_latest() {
    local x=$(__z_starship_url_latest)
    local y=$(__z_curl_location "$x")
    ## hackish strip, e.g.:
    ## from: https://github.com/starship/starship/releases/download/v0.50.0/starship-x86_64-unknown-linux-musl.tar.gz
    ## to:   v0.50.0
    y=${y:h:t}
    [ "${y:0:1}" = 'v' ] && y=${y:1}
    echo "$y"
}

__z_starship_detect_arch() {
    local arch=${ZSHU[mach]}
    case "${arch}" in
    x86_64)  [ "$(getconf LONG_BIT)" -eq 32 ] && arch=i686 ;;
    aarch64) [ "$(getconf LONG_BIT)" -eq 32 ] && arch=arm ;;
    esac
    echo "${arch}"
}

__z_starship_detect_platform() {
    local platform=${ZSHU[uname]}
    case "${ZSHU[uname]}" in
    msys_nt*)   platform=pc-windows-msvc ;;
    cygwin_nt*) platform=pc-windows-msvc ;;
    mingw*)     platform=pc-windows-msvc ;;
    linux)      platform=unknown-linux-musl ;; ## static builds
    darwin)     platform=apple-darwin ;;
    freebsd)    platform=unknown-freebsd ;;
    esac
    echo "${platform}"
}

## $1 - arch
## $2 - platform
__z_starship_detect_target() {
    local target="$1-$2"
    case "${target}" in
    arm-unknown-linux-musl) target="${target}eabihf" ;;
    esac
    echo "${target}"
}

__z_starship_auto_target() {
    [ -n "${ZSHU[starship_target]}" ] && echo "${ZSHU[starship_target]}" && return
    local arch=$(__z_starship_detect_arch)
    local platform=$(__z_starship_detect_platform)
    local target=$(__z_starship_detect_target "${arch}" "${platform}")
    echo "${target}"
}

__z_starship_install() {
    local ver=${1:-latest}
    local target url resp
    target=$(__z_starship_auto_target)
    if [ "${ver}" = 'latest' ] ; then
        url=$(TARGET=${target} __z_starship_url_latest)
        resp=$(__z_curl_response "${url}")
        resp=${resp:-400}
        [ ${resp} -ge 400 ] && return 1
    else
        url=$(TARGET=${target} __z_starship_url_versioned "${ver}")
        resp=$(__z_curl_response "${url}")
        resp=${resp:-400}
        if [ ${resp} -ge 400 ] ; then
            ## last resort: try messing with version ;D
            if [ "${ver:0:1}" = 'v' ] ; then
                ver=${ver:1}
            else
                ver="v${ver}"
            fi
            url=$(TARGET=${target} __z_starship_url_versioned "${ver}")
            resp=$(__z_curl_response "${url}")
            resp=${resp:-400}
            [ ${resp} -ge 400 ] && return 1
        fi
    fi

    local t=$(mktemp -d)
    local f="$t/starship.tar.gz"
    command curl -sqL "${url}" > "$f"
    command tar -C "$t" -xf "$f" starship &>/dev/null
    if [ $? -ne 0 ] ; then
        ## last resort
        command tar -C "$t" --strip-components=1 --wildcards -xf "$f" '*/starship' &>/dev/null
        if [ $? -ne 0 ] ; then
            rm -rf "$t"
            return 1
        fi
    fi
    local d=$(__z_starship_auto_path)
    mv "$t/starship" "$d/"
    local r=$?
    if [ $r -eq 0 ] ; then
        [ "${ver:0:1}" = 'v' ] && ver=${ver:1}
        echo "starship: installed ${ver} version in $d/" 1>&2
    fi
    rm -rf "$t"
    return $r
}

z-starship-target-available() {
    local target url resp
    target=$(__z_starship_auto_target)
    url=$(TARGET=${target} __z_starship_url_latest)
    resp=$(__z_curl_response "${url}")
    resp=${resp:-400}
    if [ ${resp} -lt 400 ] ; then
        echo "starship: available for ${target}" 1>&2
        return 0
    else
        echo "starship: NOT available for ${target}" 1>&2
        return 1
    fi
}

z-starship-update-available() {
    local target=$(__z_starship_auto_target)
    local installed=$(__z_starship_ver_installed)
    local latest=$(TARGET=${target} __z_starship_ver_latest)
    if [ -z "${latest}" ] ; then
        echo "starship: update is NOT available" 1>&2
        return 1
    fi
    if [ -z "${installed}" ] ; then
        echo "starship: NOT installed, install it 1st" 1>&2
        return 0
    fi
    local tailver=$(printf '%s\n' "${installed}" "${latest}" | sort -Vu | tail -n 1)
    if [ "${installed}" = "${tailver}" ] ; then
        if [ "${installed}" = "${latest}" ] ; then
            echo "starship: local version is up to date" 1>&2
        else
            echo "starship: local version is newer! o_O" 1>&2
        fi
        return 1
    else
        echo "starship: update is available (${installed} -> ${latest})" 1>&2
        return 0
    fi
}

z-starship-init() {
    [ -n "${ZSHU[starship_init]}" ] && return
    __z_starship_test || return
    eval "$(__z_starship init zsh)"
    ZSHU[starship_init]=1
}

z-starship-install() {
    z-starship-target-available || return
    __z_starship_install || \
    echo "starship: unable to install" 1>&2
}

z-starship-update() {
    z-starship-update-available || return 0
    __z_starship_install || \
    echo "starship: unable to update" 1>&2
}